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Commit ccf58cb4 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
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[media] vb2: fix videobuf2-core.h comments 



A lot of work was done in vb2 to regulate how drivers and the vb2 core handle
buffer ownership, but inexplicably the videobuf2-core.h comments were never
updated. Do so now. The same was true for the replacement of the -ENOBUFS
mechanism by the min_buffers_needed field.

Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent 5d0360a4

include/media/videobuf2-core.h

+10 −6
Original line number Diff line number Diff line
@@ -294,15 +294,19 @@ struct vb2_buffer { 
 *			of already queued buffers in count parameter; driver

 *			can return an error if hardware fails, in that case all

 *			buffers that have been already given by the @buf_queue

 *			callback are invalidated.

 *			If there were not enough queued buffers to start

 *			streaming, then this callback returns -ENOBUFS, and the

 *			vb2 core will retry calling @start_streaming when a new

 *			buffer is queued.

 *			callback are to be returned by the driver by calling

 *			@vb2_buffer_done(VB2_BUF_STATE_DEQUEUED).

 *			If you need a minimum number of buffers before you can

 *			start streaming, then set @min_buffers_needed in the

 *			vb2_queue structure. If that is non-zero then

 *			start_streaming won't be called until at least that

 *			many buffers have been queued up by userspace.

 * @stop_streaming:	called when 'streaming' state must be disabled; driver

 *			should stop any DMA transactions or wait until they

 *			finish and give back all buffers it got from buf_queue()

 *			callback; may use vb2_wait_for_all_buffers() function

 *			callback by calling @vb2_buffer_done() with either

 *			VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use

 *			vb2_wait_for_all_buffers() function

 * @buf_queue:		passes buffer vb to the driver; driver may start

 *			hardware operation on this buffer; driver should give

 *			the buffer back by calling vb2_buffer_done() function;